Diane Keaton is standing in front of a floor-to-ceiling window, backlighted by Los Angeles' late afternoon sun. Even appearing as just a shadowy silhouette blown out by the light, Keaton's shape is an iconic one.

There are the distinct lines of a charcoal gray hat with a grosgrain band, small rectangular eyeglasses and a nipped-waist, men's style coat that is well balanced with the full skirt and stiletto sandals that fall below it.

It's classic Keaton — neatly tailored, a little eccentric, covered up and conservative in a kooky sort of way. Even her nails have the menswear-inspired look she has been known for since her Academy Award-winning turn as Annie Hall in 1977.

"Stickers!" the 69-year-old actress exclaims of the ivory and black houndstooth-check decals she has plastered to her neatly trimmed nails. Keaton prefers the nail stickers to polish for practical reasons: because they won't chip.

Perhaps more important than sticking to the nail decals as a dedicated part of her beauty regimen, Keaton is adamant about wearing sunscreen. After being diagnosed with basal cell carcinoma at age 21 and more recently with squamous cell cancer, which was removed through two surgeries, Keaton is a vocal proponent of proper sun care. She has been a L'Oreal Paris spokeswoman since 2006 and counts the brand's sunblock as something she is never found without.

She says that her ever-present hats also help protect her face from the sun, and she still has the area where the squamous cell cancer was removed checked often.

Besides her dedicated use of sunscreen, Keaton says that the rest of her beauty routine is quite simple. She has always been diligent about using a face cream day and night and swears by eyeliner and lipstick for her everyday makeup look.

"I like to accentuate the shape of my eyes," she says, "They go down, and I like that they go down. It happens more as you get older. My dad had eyes like that. He's passed on and I like to think we're sharing the same eyes, that I'm taking his eyes with me."

As for lipstick, Keaton would like to wear red, but says the shade doesn't suit her coloring. Coral and warm rose-brown tones are more her speed.

But other than wearing sunscreen and avoiding red, this woman who has come to redefine traditional style and beauty ideals stays flexible.

"Beauty is like the word 'love,' it's humongous, it encompasses everything," she says. "I see it differently than I used to and it keeps changing and evolving, and that's what beauty needs to do, it needs to keep changing and evolving because that's how powerful it is. It's important."